import { isString, isUndefined } from '@sindresorhus/is';
import { z } from 'zod/v4';
import { logger } from '../../../logger/index.ts';
import { regEx } from '../../../util/regex.ts';
import {
  LooseArray,
  LooseRecord,
  Nullish,
} from '../../../util/schema-utils/index.ts';
import { MaybeTimestamp } from '../../../util/timestamp.ts';
import type { Release, ReleaseResult } from '../types.ts';

export const MinifiedArray = z
  .array(z.record(z.string(), z.unknown()))
  .transform((xs) => {
    // Ported from: https://github.com/composer/metadata-minifier/blob/main/src/MetadataMinifier.php#L17
    if (xs.length === 0) {
      return xs;
    }

    const prevVals: Record<string, unknown> = {};
    for (const x of xs) {
      for (const key of Object.keys(x)) {
        prevVals[key] ??= undefined;
      }

      for (const key of Object.keys(prevVals)) {
        const val = x[key];
        if (val === '__unset') {
          delete x[key];
          prevVals[key] = undefined;
          continue;
        }

        if (!isUndefined(val)) {
          prevVals[key] = val;
          continue;
        }

        if (!isUndefined(prevVals[key])) {
          x[key] = prevVals[key];
          continue;
        }
      }
    }

    return xs;
  });
export type MinifiedArray = z.infer<typeof MinifiedArray>;

export const ComposerRelease = z.object({
  version: z.union([z.string(), z.number().transform((v) => v.toString())]),
  homepage: z.string().nullable().catch(null),
  source: z.object({ url: z.string() }).nullable().catch(null),
  time: MaybeTimestamp,
  ['published-time']: Nullish(MaybeTimestamp),
  require: z.object({ php: z.string() }).nullable().catch(null),
  abandoned: z.union([z.string(), z.boolean()]).optional().catch(undefined),
});
export type ComposerRelease = z.infer<typeof ComposerRelease>;

export const ComposerReleases = z
  .union([
    MinifiedArray.pipe(LooseArray(ComposerRelease)),
    LooseRecord(ComposerRelease).transform((map) => Object.values(map)),
  ])
  .catch([]);
export type ComposerReleases = z.infer<typeof ComposerReleases>;

export const ComposerPackagesResponse = z
  .object({
    packageName: z.string(),
    packagesResponse: z.object({
      packages: z.record(z.string(), z.unknown()),
    }),
  })
  .transform(
    ({ packageName, packagesResponse }) =>
      packagesResponse.packages[packageName],
  )
  .transform((xs) => ComposerReleases.parse(xs));
export type ComposerPackagesResponse = z.infer<typeof ComposerPackagesResponse>;

export function parsePackagesResponse(
  packageName: string,
  packagesResponse: unknown,
): ComposerReleases {
  try {
    return ComposerPackagesResponse.parse({ packageName, packagesResponse });
  } catch (err) {
    logger.debug(
      { packageName, err },
      `Error parsing packagist response for ${packageName}`,
    );
    return [];
  }
}

export function extractReleaseResult(
  ...composerReleasesArrays: ComposerReleases[]
): ReleaseResult | null {
  const releases: Release[] = [];
  let homepage: string | null | undefined;
  let sourceUrl: string | null | undefined;
  let deprecationMessage: string | undefined;

  for (const composerReleasesArray of composerReleasesArrays) {
    for (const composerRelease of composerReleasesArray) {
      const version = composerRelease.version.replace(regEx(/^v/), '');
      const gitRef = composerRelease.version;

      const dep: Release = { version, gitRef };

      // Packagist's `published-time` reflects when the version was actually published to the registry;
      // prefer it over `time` (the git tag's `releasedAt`, which could be when the commit that the tag points at was pushed, not the time the release itself was made public to the world), falling back when absent.
      const releaseTimestamp =
        composerRelease['published-time'] ?? composerRelease.time;
      if (releaseTimestamp) {
        dep.releaseTimestamp = releaseTimestamp;
      }

      if (composerRelease.require?.php) {
        dep.constraints = { php: [composerRelease.require.php] };
      }

      if (composerRelease.abandoned) {
        dep.isDeprecated = true;
        deprecationMessage ??= getAbandonedMessage(composerRelease.abandoned);
        // TODO #44060 when `abandoned` is a package name, emit replacementName/replacementVersion to open a replacement PR
      }

      releases.push(dep);

      if (!homepage && composerRelease.homepage) {
        homepage = composerRelease.homepage;
      }

      if (!sourceUrl && composerRelease.source?.url) {
        sourceUrl = composerRelease.source.url;
      }
    }
  }

  if (releases.length === 0) {
    return null;
  }

  const result: ReleaseResult = { releases };

  if (homepage) {
    result.homepage = homepage;
  }

  if (sourceUrl) {
    result.sourceUrl = sourceUrl;
  }

  if (deprecationMessage) {
    result.deprecationMessage = deprecationMessage;
  }

  return result;
}

function getAbandonedMessage(abandoned: string | boolean): string {
  const message = 'This package is abandoned and no longer maintained.';
  if (isString(abandoned)) {
    return `${message} The author suggests using the \`${abandoned}\` package instead.`;
  }
  return message;
}

export function extractDepReleases(
  composerReleases: unknown,
): ReleaseResult | null {
  const parsedReleases = ComposerReleases.parse(composerReleases);
  return extractReleaseResult(parsedReleases);
}

export function parsePackagesResponses(
  packageName: string,
  packagesResponses: unknown[],
): ReleaseResult | null {
  const releaseArrays = packagesResponses.map((pkgResp) =>
    parsePackagesResponse(packageName, pkgResp),
  );
  return extractReleaseResult(...releaseArrays);
}

export const HashSpec = z.union([
  z
    .object({ sha256: z.string().nullable() })
    .transform(({ sha256 }) => ({ hash: sha256 })),
  z
    .object({ sha1: z.string().nullable() })
    .transform(({ sha1 }) => ({ hash: sha1 })),
]);
export type HashSpec = z.infer<typeof HashSpec>;

export const RegistryFile = z.intersection(
  HashSpec,
  z.object({ key: z.string() }),
);
export type RegistryFile = z.infer<typeof RegistryFile>;

export const PackagesResponse = z.object({
  packages: LooseRecord(ComposerReleases).catch({}),
});
export type PackagesResponse = z.infer<typeof PackagesResponse>;

export const PackagistFile = PackagesResponse.merge(
  z.object({
    providers: LooseRecord(HashSpec)
      .transform((x) =>
        Object.fromEntries(
          Object.entries(x).map(([key, { hash }]) => [key, hash]),
        ),
      )
      .catch({}),
  }),
);
export type PackagistFile = z.infer<typeof PackagistFile>;

export const RegistryMeta = z
  .record(z.string(), z.unknown())
  .catch({})
  .pipe(
    PackagistFile.merge(
      z.object({
        ['includes']: LooseRecord(HashSpec)
          .transform((x) =>
            Object.entries(x).map(([name, { hash }]) => ({ key: name, hash })),
          )
          .catch([]),
        ['provider-includes']: LooseRecord(HashSpec)
          .transform((x) =>
            Object.entries(x).map(([key, { hash }]) => ({ key, hash })),
          )
          .catch([]),
        ['providers-lazy-url']: z.string().nullable().catch(null),
        ['providers-url']: z.string().nullable().catch(null),
        ['metadata-url']: z.string().nullable().catch(null),
        ['available-packages']: z.array(z.string()).nullable().catch(null),
      }),
    ),
  )
  .transform(
    ({
      ['includes']: includesFiles,
      ['packages']: packages,
      ['provider-includes']: files,
      ['providers']: providerPackages,
      ['providers-lazy-url']: providersLazyUrl,
      ['providers-url']: providersUrl,
      ['metadata-url']: metadataUrl,
      ['available-packages']: availablePackages,
    }) => {
      const includesPackages: Record<string, ReleaseResult | null> = {};
      return {
        packages,
        includesFiles,
        providerPackages,
        files,
        providersUrl,
        providersLazyUrl,
        metadataUrl,
        includesPackages,
        availablePackages,
      };
    },
  );
export type RegistryMeta = z.infer<typeof RegistryMeta>;